Various powered vehicles are known in the agricultural and turf care industries which are movable over the ground and perform various operations on the ground or on growing vegetation. For example, combines are known for harvesting crops and large mowing machines are known for cutting grass. The Toro Company, the assignee of the present invention, manufactures and sells various large mowing machines for cutting grass over wide areas sush as golf courses and the like. These include the Parkmaster series and the HTM series of mowers.
Machines of the type noted above usually have an operator's cab or area in which a seat and steering assembly are contained. The steering assembly usually includes an upright steering column that is located in front of the seat. In addition, the steering assembly also has a rotatable steering wheel carried at the top of the steering column. It has been known in such machines to pivotally mount the steering column on the machine so that it can be adjusted towards or away from the seat. It has also been known to pivotally mount the steering wheel on the steering column so that it's tilt or angle of inclination can be adjusted relative to the seat. Both adjustments are desirable to give the operator greater comfort, both in getting in and out of the seat and also while driving the vehicle, since he can tailor the positions of the steering column and steering wheel to suit his individual requirements.
While the adjustable steering columns and steering wheels known in the prior art function effectively in giving the operator the desired movement in these components, separate locking devices have been used in the prior art to individually lock these components in an adjusted position. For example, it is quite common on the steering column to have a foot operated pedal that moves a locking flange into and out of engagement with a pawl on the steering column to lock the steering column in place. The steering wheel often has an infinite friction type lock which is released or engaged by a small lever on the steering column.
The use of two separate locking assemblies, controlled by two separate control elements (i.e. the pedal and the lever), is disadvantageous as it unnecessarily complicates the design and involves multiple components which is costly. In addition, the operator has to manipulate two control elements with two separate motions if he wants to adjust both the steering wheel and steering column positions. Since these adjustments are often required whenever the operator mounts or dismounts the machine, the need for two separate motions wastes energy and over time becomes a nuisance for the operator.